What is typically used to communicate intentions for a flight?

A flight plan is the primary tool used to communicate a pilot's intentions for a flight. It serves several important purposes in aviation. First, it informs air traffic control (ATC) about the details of the flight, including the departure and destination points, estimated times of departure and arrival, and the intended route. This information helps ATC manage the airspace and ensures safety by maintaining separation between different aircraft.

Additionally, filing a flight plan provides a measure of safety for the pilot and passengers. In the case of an emergency or an unexpected deviation from the planned route, search and rescue resources can be mobilized more effectively if they know where the aircraft was supposed to be and at what time.

Other options do not serve this critical function in communicating flight intentions. For instance, a flight logbook is primarily for recording flight hours and experiences, while a weather briefing provides information on current weather conditions but does not communicate the pilot's flight intentions. A notarized agreement is not typically used in this context of aviation operations. Thus, the flight plan clearly stands out as the primary means of communicating flight intentions.